Sheet-like structure material and manufacturing method

ABSTRACT

The invention discloses a sheet-like structure material and its manufacturing method. The sheet-like structure material has the advantages that impact imposed on its edge ends can be adsorbed to protect its adherends, and that the labor required for installing it and edge ends treatment can be significantly saved. The structure material comprises an outer peripheral structure which has elasticity and is integrally formed at the outer periphery of a sheet-like composite body comprising two glass sheets and an intermediate resin layer disposed between the glass sheets. The outer peripheral structure is formed from a resinous material used for forming the intermediate resin layer, by allowing the material to ooze from between the glass sheets.

This application is a divisional of prior application Ser. No.09/172,252 filed Oct. 14, 1998.

TECHNICAL FIELD

The present invention relates to a sheet-like structure material havingan intermediate resin layer between two adherends such as glass sheets.The invention also relates to a method for manufacturing the sheet-likestructure material.

BACKGROUND ART

Known laminated glass is formed from two sheets of plate glass with anadhesive film between, the whole being laminated together bythermocompression bonding. In such laminated glass 51, the edge ends ofglass sheets 52, 53 around the periphery are uncovered as shown in FIG.5(a).

The glass sheets are liable to break off if a something strikes againsttheir uncovered edge ends. When such laminated glass 51 is fit into aframework 54 such as a metallic sash as shown in FIG. 5(b), the edgeends of the glass sheets 52, 53 come into direct contact with theframework 54. In this condition, if the framework 54 is rapidly cooled,the grass sheets 52, 53 will be cracked because of the difference intemperature between the edge ends and center of each glass sheet. Notethat reference numeral 55 in FIG. 5(b) represents a rubber seal.

To solve this problem, when the laminated glass 51 is fit into theframework 54 such as a metallic sash, a setting block (heat insulatingblock) 56 is usually placed under the laminated glass 51 as shown inFIG. 5(c), thereby interrupting heat transmission between the glasssheets 52, 53 and the framework 54.

However the setting block process is employed, there still remains therisk of braking the unprotected edge ends of the pane duringtransportation and handling. Further, the conventional method shown inFIG. 5(c) requires the installation of the setting block, resulting incomplicated fitting process. Another disadvantage is that when applyingfinishing treatment to the laminated glass according to the conventionalprocess, it is very troublesome to chamfer the edge ends of thelaminated glass and particularly to finish the gradually changed edgefrom round cut corner to the straight cut in the laminated glass.

The present invention is directed to overcoming the foregoing problemsand it is accordingly a primary object of the invention to provide asheet-like structure material and its manufacturing method, thesheet-like structure material being capable of absorbing impact imposedon its edge ends to protect its adherends and requiring much less laborfor installation work and end face treatment.

DISCLOSURE OF THE INVENTION

The above object can be achieved by a sheet-like structure materialembodying the invention, wherein an outer peripheral structure havingelasticity is integrally formed at the outer periphery of a sheet-likecomposite body comprising a first adherend, a second adherend and anintermediate resin layer sandwiched between the first and secondadherends.

According to the invention, the outer periphery of a sheet-likecomposite body comprising two adherends and an intermediate resin layeris integrally surrounded by an outer peripheral structure havingelasticity. With this arrangement, even if impact is imposed on the edgeends of the sheet-like structure material such as laminated glass, theimpact is adsorbed by the outer peripheral structure, thereby protectingthe sheet-like composite body. Further, the edges of the adherends donot hurt the workers who deal with the sheet-like structure material.When setting the sheet-like structure material in a framework such as asash, the adherends such as glass do not come into direct contact withthe framework, which brings about heat insulating effects. Therefore,even if the framework is rapidly cooled, the edge ends of each adherendwill not differ from its center in temperature, so that there is nodanger of cracking the adherends. When setting the sheet-like structurematerial of the invention in a framework or when applying chamferingtreatment to its edge ends, no complicated process is involved. Itshould be noted that the thickness of the outer peripheral structure canbe arbitrarily determined according to the size of the framework.

In the invention, the outer peripheral structure may be formed from aresinous material from which the intermediate resin layer is to beformed and which is oozing from between the first and second adherends.With this, not only can the outer peripheral structure be formed withease, for example, by injection and press molding but also the outerperipheral structure can be easily adhered to other outer peripheralmembers since the resinous material of the outer peripheral structureserves as an adhesive agent. In this injection and press molding, theintermediate resin layer and the outer peripheral structure are formedby spreading the molten resinous material through uniform application ofpressure to the whole molten resinous material. The molded productproduced by this method is free from defects in joining the adherends tothe resin layer. Additionally, no stress strain is generated in thismethod since the resin layer is formed by uniformly applying pressure tothe whole molten resinous material so as to cause the material tospread. The outer peripheral structure may be formed from only the sameresinous material as that of the intermediate resin layer. In this case,the outer peripheral structure and the sheet-like composite body can bemolded at the same time, which simplifies the molding process.Alternatively, the outer-peripheral structure may be composed of a partformed from the same resinous material as that of the intermediate resinlayer and a part formed from a resinous material different from theresinous material of the intermediate resin layer. This alternativeembodiment can be put in practice by only interposing a member (i.e.,outer peripheral member), which is made of a material different from theresinous material of the intermediate resin layer, between the diesduring molding so that the outer peripheral member is easily formed inan integral manner. This makes it possible to produce highly value-addedproducts through a simple molding process.

Preferably, the resinous material of the intermediate resin layer is athermoplastic resinous material having a tensile elastic modulus of1,000 kg/cm² or less. Use of such a thermoplastic resinous material canprevent the adherends such as glass from breaking even if the resinousmaterial contracts or expands owing to changes in temperature. Thethermoplastic resinous material is selected from thermoplasticelastomers (TPE) including polyvinyl butyral (PVB), ethylene-vinylacetate copolymer (EVA) and thermoplastic polyurethane (TPU). Thesematerials are preferable, particularly when forming the outer peripheralstructure and the intermediate resin layer from the same material.

Preferable examples of the material different from the resinous materialof the intermediate resin layer include neoprene rubber, wood, neoprenerubber foam, urethane foam, polypropylene foam and polyethylene foam.Use of a material selected from the above examples allows the resultantsheet-like structure material to be used in various applications.

The first and second adherends may be formed from the same material ordifferent materials selected from inorganic materials such as glass andsilicon and from organic materials such as polycarbonate and acrylicresin. Use of such materials allows the resultant sheet-like structurematerial to be used in various applications such as the front glass,side glass and rear glass of automobiles and ordinary buildingmaterials.

According to the invention, there is provided a first method formanufacturing a sheet-like structure material, comprising the steps of:

placing a first adherend and a second adherend between dies in acompression molding machine so as to be in close contact with the diesrespectively;

filling a mold cavity with a molten resinous material to integrally moldan intermediate resin layer and an outer peripheral structure, theintermediate resin layer being formed between the first and secondadherends, the outer peripheral structure having elasticity and beingformed at the outer peripheries of the first and second adherends and ofthe intermediate resin layer.

According to the above sheet-like structure material manufacturingmethod, the first and second adherends are placed between the dies ofthe compression molding machine and brought into close contact with thedies respectively, for instance, by vacuum suction. In this condition,the mold cavity is filled with a molten resinous material so that theintermediate resin layer is formed from this molten resinous materialbetween the first and second adherends, integrally with the outerperipheral structure which has elasticity and is formed from the moltenresinous material oozing from between the first and second adherends,enclosing the outer peripheries of the adherends and the intermediateresin layer. The configuration of the outer peripheral structure is thusformed by transferring a die pattern to the molding resin and thereforeeven if the finished pane shape has a round cut or straight cut shape,elaborate finishing can be easily accomplished by molded peripheralstructure.

According to the invention, there is provided a second method formanufacturing a sheet-like structure material, comprising the steps of:

placing a first adherend and second adherend between dies in acompression molding machine so as to be in close contact with the diesrespectively;

placing a preformed outer peripheral member at the outer peripheries ofthe first and second adherends;

filling a mold cavity with a molten resinous material to integrally moldan intermediate resin layer, an outer peripheral structure and an outerperipheral member, the intermediate resin layer being formed between thefirst and second adherends, the outer peripheral structure havingelasticity and being formed at the outer peripheries of the adherendsand of the intermediate resin layer.

In the above sheet-like structure material manufacturing method, thefirst and second adherends are placed between the dies of a compressionmolding machine and brought into close contact with the diesrespectively, for instance, by vacuum suction. At the same time, apreformed outer peripheral member is placed at the outer peripheries ofthe adherends. In this condition, the mold cavity is filled with amolten resinous material. As a result, the intermediate resin layer isformed between the first and second adherends, from this molten resinousmaterial. From the molten resinous material oozing from between thefirst and second adherends, the outer peripheral structure havingelasticity is formed so as to enclose the outer peripheries of theadherends and of the intermediate resin layer. The outer peripheralmember is adhered to (combined with) the outer peripheral structure sothat the adherends, the intermediate resin layer, the outer peripheralstructure and the outer peripheral member are all integrated. Thismethod can provide highly value-added products, by suitably selectingmaterial and shape for the outer peripheral member.

In both of the above manufacturing methods, when filling the mold cavitywith the molten resinous material, it is preferred to performcompression molding by clamping both dies so as to uniformly applypressure to the whole molten resinous material, thereby causing thematerial to spread. With this arrangement, defects in joining theadherends and the intermediate resin layer can be avoided and no stressstrain is generated because the intermediate resin layer is formed byspreading the molten resinous material through uniform application ofpressure to the whole molten resinous material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cut perspective view of a sheet-like structurematerial manufactured according to a first embodiment of the invention.

FIGS. 2(a) to 2(e) illustrate steps for manufacturing the sheet-likestructure material according to the first embodiment.

FIGS. 3(a) and 3(b) show one example of molded products manufacturedaccording to the first embodiment.

FIGS. 4(a) and 4(b) show one example of molded products manufacturedaccording to a second embodiment of the invention.

FIGS. 5(a) 5(b), and 5(c) show laminated glass according to a prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to the drawings, preferred embodiments of the sheet-likestructure material and manufacturing method according to the inventionwill be explained.

First Embodiment

FIG. 1 shows a partially cut perspective view of a pane of laminatedglass embodying the sheet-like structure material of a first embodimentof the invention.

The laminated glass pane 1 has a laminated structure comprisingrectangular glass sheets 2, 3 serving as the first and second adherends;an intermediate resin layer 4 formed from a thermoplastic resinousmaterial and sandwiched between the glass sheets 2, 3; and an outerperipheral structure 5 that is formed at the outer periphery of thelaminated glass pane 1 integrally with the intermediate resin layer 4,being made of the same resinous material as that of the intermediateresin layer 4.

The resinous material of the intermediate resin layer 4 and the outerperipheral structure 5 is adhesive to the glass sheets 2, 3 and hasrubber-like elasticity so that it adsorbs a shock to protect the glasssheets 2, 3 if impact is imposed on the edge ends of the glass sheets 2,3. The resinous material preferably has a tensile elastic modulus of1,000 kg/cm² or less so that it does not cause damage to the glasssheets 2, 3 even if it contracts or expands. Such a resinous material isselected from thermoplastic elastomers (TPE) including polyvinyl butyral(PVB), ethylene-vinyl acetate copolymer (EVA) and thermoplasticpolyurethane (TPU). These resinous materials have low heatconductivities that are about one forth the heat conductivity of glass.For instance, PVB has a heat conductivity of 0.14 kcal/mh° C. at 20° C.,while glass has a heat conductivity of 0.65 kcal/mh° C. at 0° C. Theseresinous materials have heat insulating effects so that when thelaminated glass pane 1 is attached to a framework such as a sash, theglass sheets 2, 3 do not come into direct contact with the framework andare not affected by temperature changes by virtue of the heat insulatingeffects of the resinous material.

The laminated glass pane 1 is produced in the following manufacturingprocess (see FIG. 2), using a compression molding machine.

(1) Setting Step

While a movable die 7 being opened with respect to a fixed die 6, theglass sheets 2, 3 are respectively placed at their specified positionswithin the dies 6, 7. Specifically, the glass sheets 2, 3 are held onthe center of each die by vacuum suction such that a mold cavity iscreated so as to surround the glass sheets 2, 3 and that the glasssheets 2, 3 are respectively in close contact with the surface of eachdie 6, 7 without a clearance between.

(2) Die Closing and Movable Die Locking Step (FIG. 2(a))

The movable die 7 is forwardly moved to the fixed die 6 until aspecified spacing 1 ₁ (not shown) is obtained between the glass sheets2, 3 and then the movable die 7 is locked. Subsequently, the movable die7 is moved toward the fixed die 6 until the spacing between the glasssheets 2, 3 becomes equal to compression allowance 1 ₂ (1 ₂<1 ₁).

(3) Injection Feeding Step (FIG. 2(b))

When the movable die 7 and the fixed die 6 are positioned with thespacing between the glass sheets 2, 3 being equal to the compressionallowance 1 ₂, an opening/closing valve 9 disposed at a nozzle 8 of theinjection unit is opened and a injector (not shown) disposed on the baseside is operated to move forward, whereby a molten resinous material 12is injected into a mold cavity 11 through a gate 10.

(4) Mold Cavity Compression Step (FIG. 2(c))

During the injection of the molten resinous material 12 into the moldcavity 11, the movable die 7 is forwardly moved to the fixed die 6 toreduce the volume of the mold cavity 11 while keeping the dies 6, 7parallel to each other. With this operation, pressure is uniformlyapplied to the whole molten resinous material 12 being injected, therebycausing the material to spread. Note that the pressure applied to themolten resinous material 12 is high enough to restrict the developmentof gas contained in the molten resinous material 12 into air bubbles.The forward moving (compression) amount of the movable die 7 at thattime corresponds to the length obtained by subtracting the finalthickness of the resin present between the glass sheets 2, 3 from thecompression allowance 1 ₂. It should be noted that when the moltenresinous material 12 has been injected into the molding cavity 11 in anamount required for molding, the opening/closing valve 9 is closed.

(5) Holding and Cooling Step (see FIG. 2(d))

After reducing the volume of the molding cavity 11, holding pressure isapplied to hold the dies until the spread, molten resinous material 12is cooled and joined to the surfaces of the glass sheets 2, 3.

(6) Die Opening and Ejecting Step (see FIG. 2(e))

The movable die 7 is unlocked to allow the movable die 7 to movebackward and then the molded product is removed from the dies.

As described above, the outer peripheral structure 5 on the periphery ofthe laminated glass pane 1 is formed from the resinous material forforming the intermediate resin layer 4, which is oozing from between theadherends, that is, the two glass sheets 2, 3. Therefore, the outerperipheral structure 5 can be easily molded using a compression moldingmachine. Further, for setting the laminated glass pane 1 in a frameworksuch as a sash, installation work as well as chambering of edge ends canbe extremely simplified. The thickness of the outer peripheral structure5 can be arbitrarily determined according to the size of the frameworkand sides which are not surrounded by the outer peripheral structure canbe formed if necessary, only by substantially eliminating the cavitybetween the glass sheets 2, 3 and the dies. FIG. 3 shows one example ofmolded products produced according to this embodiment (FIG. 3(a) is afront view and FIG. 3(b) is a partial view taken on line A—A of FIG.3(a)). In this example, a setting block (heat insulating block) 13 isformed in an integral manner under the laminated glass pane 1, as partof the outer peripheral structure.

According to the first embodiment, even if impact is imposed on the edgeends of the laminated glass pane 1, the outer peripheral structure 5adsorbs the impact thereby protecting the glass sheets 2, 3.Additionally, the edge ends of the glass sheets 2, 3 do not hurt theworkers. When setting the laminated glass pane 1 in a framework such asa sash, the edge ends of the glass sheets 2, 3 do not come into directcontact with the framework so that desired heat insulating effects canbe achieved and as a result, even if the framework is rapidly cooled,the glass sheets 2, 3 are not liable to crack due to the difference intemperature between their edge ends and center of the parts. Since theouter peripheral structure 5 constitutes the edge ends of the laminatedglass pane 1, there is no need to apply treatment such as chamfering andpolishing the edge ends of the laminated glass.

In cases where the part of the mold cavity 11 which corresponds to theouter peripheral structure is thick as shown in FIG. 2 and such a moldcavity 11 is charged by ordinary injection molding, an undesirablesituation is often encountered in which the thick part corresponding tothe outer peripheral structure is first filled with the resinousmaterial and then, the resinous material gets stuck, causing adifficulty in filling the thin part, or in which there arises adifficulty in molding if the flow rate of the resinous material dropsduring filling of the thick part. This problem can be solved by the useof the above-described molding method (injection and press molding) sothat the product such as described in this embodiment can be easilyproduced.

Second Embodiment

FIGS. 4(a) and 4(b) show a front view and partial cross sectional viewtaken on line B—B, respectively, of a molded product manufacturedaccording to a second embodiment of the invention.

While there has been described in the first embodiment a laminated glasspane having the outer peripheral structure 5 and the intermediate resinlayer 4 which are formed from the same material, a laminated glass pane20 according to the second embodiment has an outer peripheral structure21 composed of a first portion 23, a second portion 24 and a thirdportion 25, the first portion 23 being made of the same material as thatof an intermediate resin layer 22 and formed so as to cover the endfaces of the glass sheet 2, 3, the second and third portions 24, 25being made of materials different from that of the intermediate resinlayer 22 and formed outside the first portion 23. The second portion 24is a safety block and the third portion 25 is sealing rubber. In FIG. 4,reference numeral 26 designates a framework such as a sash.

For producing the laminated glass pane 20 of this embodiment, preformedouter peripheral members (corresponding to the second and third portions24, 25) are placed within the dies and then, injection and press moldingsimilar to the first embodiment is carried out. During the molding, theresinous material for forming the intermediate resin layer 22 oozes frombetween the glass sheets 2, 3, forming the first portion 23 of the outerperipheral structure 21. The second portion 24 and third portion 25placed on the edge corner side and side face side, respectively, of thefirst portion 23, are integrally joined to (combined with) the firstportion 23, thereby completing the molding.

In this embodiment, examples of the materials of the outer peripheralmembers include neoprene rubber, wood, neoprene rubber foam, urethanefoam, polypropylene foam and polyethylene foam.

According to the second embodiment, by simply interposing an outerperipheral member between the dies during molding, the outer peripheralmember made of a material different from the resinous material of theintermediate resin layer and the intermediate resin member can be easilymolded in an integral manner, so that laminated glass having a settingblock or sealing rubber integral therewith can be easily formed. Thismeans that highly value-added products can be manufactured through asimple molding process, by adopting -the method of the secondembodiment. In addition, if the outer peripheral structure 5 of thelaminated glass according to the first embodiment is vulnerable tochemical attack for instance, this problem may be solved by joining anouter peripheral member to the laminated glass as described in thesecond embodiment, so that the outer peripheral structure 5 is no longerexposed to chemically harmful environment.

Although glass sheets are used as the adherends in the first and secondembodiments, other inorganic materials such as silicon and organicplastic materials such as polycarbonate and acrylic resin may be usedsolely or in combination for the adherends.

What is claimed is:
 1. A method for manufacturing a composite sheetmaterial, comprising the steps of: placing a first adherend and a secondadherend between dies in a compression molding machine so as to be inclose contact with the dies respectively; filling a mold cavity with amolten resinous material to integrally mold as a single piece anintermediate resin layer and an outer peripheral structure, theintermediate resin layer being formed between and in direct contact withthe first and second adherends, the outer peripheral structure havingimpact absorbing properties and being formed at the outer peripheries ofthe first and second adherends and of the intermediate resin layer so asto adhere to and cover total outer peripheries of said first and secondadherends, said outer peripheral structure being of a material having atensile elastic modulus of 1,000 kg/cm² or less.
 2. A composite sheetmaterial manufacturing method according to claim 1, wherein when fillingthe mold cavity with the molten resinous material, compression moldingis performed by clamping both dies so as to uniformly apply pressure tothe whole molten resinous material, thereby causing the material tospread.
 3. A method for manufacturing a composite sheet material,comprising the steps of: placing a first adherend and second adherendbetween dies in a compression molding machine so as to be in closecontact with the dies respectively; placing a preformed outer peripheralmember spaced from the outer peripheries of the first and secondadherends; filling a mold cavity with a molten resinous material tointegrally mold an intermediate resin layer and an outer peripheralstructure for adhering to said peripheral member, the intermediate resinlayer being formed between the first and second adherends, the outerperipheral structure having impact absorbing properties and being formedat the outer peripheries of the adherends and of the intermediate resinlayer, said outer peripheral structure being of a material having atensile elastic modulus of 1,000 kg/cm² or less.
 4. A composite sheetmaterial manufacturing method according to claim 3, wherein when fillingthe mold cavity with the molten resinous material, compression moldingis performed by clamping both dies so as to uniformly apply pressure tothe whole molten resinous material, thereby causing the material tospread.